Re: root:// protocol

Rene Brun (Rene.Brun@cern.ch)
Tue, 24 Mar 1998 18:28:45 +0100

O'NEEL Bruce wrote:
>
> Hi,
> In looking at http://root.cern.ch/root/NetFile.html two questions
> come to mind.
>
> 1. Is there some documentation on the root:// protocal
> 2. Can you access other files other than root ones, ie, does rootd
> know something about root files, or, is it just sending the byte
> ranges you ask for.
>
> I'm interested in them because I'd like to add a root:// protocal
> handler to cfitsio to match it with the ftp:// and http:// protocal
> handlers, and, I'd prefer not to reverse engineer it from the code if
> possible. While we're at it, is the source for rootd available?
>

rootd is described at URL: http://root.cern.ch/root/NetFile.html

You can import the source file for rootd via URL
ftp://root.cern.ch/root/rootd.tar.gz

rootd itself does not know anything about the Root files.
It is a simple program (1000 lines) that controls user access,
open/close files and read/write a stream of bytes from/to a
byte address in the file.
I would suggest you look into the well documented source file
to see what the current protocol is doing. Extending the protocol
should be pretty easy.
In the case of Root itself, the class TNetFile exploit the root
protocol.
TNetFile is derived from TFile and redefines only the functions
writing/reading a stream of bytes at a very low level.

Rene Brun